Normalised star formation rate, SFR_NORM, as a function of rest-frame absorption-corrected X-ray luminosity. Blue (green) colour indicates the samples after (before) applying the quality criteria when including the full sample (circles) and when considering only sources with spectroscopic redshifts (asterisks). In each case, we divided the sample into three bins of equal size and show the median values of logSFR_NORM and logL_X with uncertainties calculated using the bootstrap resampling method. The grey squares represent the mean values of the full sample after applying the quality criteria.